HS Code, SDS and Two More Sheets a SAP Container Needs at the Port

Eleven days at a port, 180 dollars a day in demurrage, and a customer line that ran out of powder on day six. What held the container was an argument between a forwarder and a carrier about whether super absorbent powder needed a dangerous goods declaration. The SDS said “not regulated” in section 14. The carrier wanted a signed statement saying so. Nobody had one.

Super absorbent polymer is not dangerous goods. It is also not a cargo that clears itself, and the paperwork that gets it moving sits in four documents that are usually assembled by three different people.

Classification first

Most crosslinked sodium polyacrylate ships under HS 3906.90, the heading for other acrylic polymers in primary forms. Some customs authorities will accept 3907.99 if the product is described as a polyether or a modified natural polymer, and a few will challenge either if the invoice description is vague. The classification is decided by the polymer chemistry, not by the end use, so a powder sold for diapers and the same powder sold for sludge treatment carry the same code.

If you ship regularly to one country, ask the importer to obtain a binding ruling. It costs a little and removes the argument permanently, because a ruling is a decision the authority has to stand behind.

The four documents

A commercial invoice with a description a customs officer can match to a tariff line: chemical name, polymer type, physical form, and intended use. “Polymer resin” alone invites a query.

A safety data sheet with all sixteen sections, where section 14 states the transport status explicitly and section 9 gives the dust hazard. An SDS written for a different product with the name changed is worse than no SDS, because it will contradict the invoice.

A non-hazardous cargo declaration on company letterhead, signed, naming the UN numbers considered and rejected. This is the sheet that was missing in the case above, and it is the one carriers ask for at the gate.

A packing list with net and gross weight per pallet, plus the ISPM 15 stamp on any wooden pallet. A container that arrives with unstamped wood is fumigated or refused, and both outcomes cost more than the stamp.

Weight and volume declarations deserve a second look for a powder that absorbs water from the air. A container loaded in a humid port can gain several hundred kilograms of moisture across a long sea route, and the discharge weighbridge will disagree with the invoice. Declare the net weight at load, note the moisture at packing on the packing list, and photograph the seal. That record has settled more disputes than any laboratory report.

The description that triggers a DG query

Words like “super absorbent”, “water blocking” and “gel forming” occasionally flag a booking system because they appear on lists for other product families. The fix is not to hide the function but to lead with the chemistry: “Sodium polyacrylate, crosslinked, powder, non-hazardous, not regulated for transport”. Functional language can follow in the second line.

One shipper learned this after a booking was rejected three times for an order going to a market where the word “absorbent” appeared on an internal restricted list. Changing the first line of the description cleared it without changing a single other document.

Keep the four sheets in one folder per shipment, with the SDS version number recorded on the invoice. When a container is held, the argument is never about chemistry; it is about which version of which document the carrier has. The SAP powder product pages carry the transport classification for each grade, which is a reasonable starting point for your own declaration.